Application of a non-stationary method in determination of the thermal properties of radiation shielding concrete with heavy and hydrous aggregate.

Highlights • Thermal properties of concrete components can be estimated by solving reverse problem. • The thermal conductivity is most preferably measured on water soaked concrete. • The specific heat is preferably measured on concrete dried to stable mass. • The rule of mixtures can predict specific heat of concrete for insufficient data. Abstract Results of measurements of the specific heat and the thermal conductivity of concrete with blended special aggregate for neutron and gamma radiation shielding are presented. Experimental tests were performed on concrete with heavyweight aggregate (magnetite, barite), hydrogen-bearing aggregate (serpentine) and amphibolite aggregate. The thermal properties of concrete were determined using a nonstationary method. The highest specific heat was found for concrete with serpentine aggregate. Simple models for predicting the specific heat and the thermal conductivity on the basis of concrete mix design were evaluated to include the blends of heavyweight and hydrogen-bearing aggregates. The thermal conductivity of concrete was found to be linearly dependent on the concrete density in the range from 2200 to 3500 kg/m3. Its increase due to water saturation of concrete was not dependent on the open porosity of concrete. It was found that the specific heat can be fairly well predicted using the rule of mixtures formula. The thermal conductivity of concrete can be approximately predicted using a parallel model in the case of water-saturated concrete. The thermal conductivity prediction for dry concrete is also discussed. [ABSTRACT FROM AUTHOR]